# Service Invocation

Dapr provides users with the ability to call other applications that have unique ids.
This functionality allows apps to interact with one another via named identifiers and puts the burden of service discovery on the Dapr runtime.

## Invoke a method on a remote Dapr app

This endpoint lets you invoke a method in another Dapr enabled app.

### HTTP Request

```http
POST/GET/PUT/DELETE http://localhost:<daprPort>/v1.0/invoke/<appId>/method/<method-name>
```

### HTTP Response codes

Code | Description
---- | -----------
200  | Request successful
500  | Request failed

### URL Parameters

Parameter | Description
--------- | -----------
daprPort | the Dapr port
appId | the App ID associated with the remote app
method-name | the name of the method or url to invoke on the remote app

```shell
curl http://localhost:3500/v1.0/invoke/countService/method/sum \
  -H "Content-Type: application/json"
```

### Sending data

You can send data by posting it as part of the request body.

```shell
curl http://localhost:3500/v1.0/invoke/countService/method/calculate \
  -H "Content-Type: application/json"
  -d '{ "arg1": 10, "arg2": 23, "operator": "+" }'
```

> The response from the remote endpoint will be returned in the request body.